Methods of transmitting and selectively reproducing announcements via the radio data system (RDS) are known. For transmitting messages via the mobile wireless network, the GSM (Global System for Mobile Communication) has been established under the European Digital Cellular Telecommunication System's ETSI standard. The digital signals in the Short Message System (SMS) channel are defined in the pr ETS 300536 draft of August 1995 and the pr ETS 300537 draft of March 1995. The SMS is transmitted simultaneously but asynchronously with the audio stream.